1. Field of the Invention
The invention relates to a press-fit assembly apparatus, and especially relates to a press-fit assembly apparatus joining two frames by rolling and pressing.
2. Description of the Prior Art
In a general assembly process of a liquid crystal display monitor, after a display module is assembled to a back casing of the monitor, the back casing needs to be joined with a front frame. If an operator joins the front frame directly to the back casing by hands, because such joining needs the operator to apply a proper force on the front frame and the back casing, the degree of fatigue of the operator increases after a long time operation. The applied force by the operation will be unsteady, leading to failure in the joining. Especially if a displaying panel of the display module is located close to where the back casing and the front frame are joined, the failure in joining may also induce cracks in the displaying panel, which increases the manufacturing cost. In addition, in a method of using fixtures to join the back casing and the front frame, e.g. applying a vertical force directly on the front frame by use of a press plate of the fixture for joining the front frame to the back casing, for completely joining the back casing and the front frame, the press plate of the fixture usually horizontally presses down the front frame in a fixed stroke. The press plate cannot press down in coordination with the actual joining situations of the back casing with the front frame. It leads to that when an inexact alignment of the back casing with the front frame occurs due to operation or manufacturing variation, a direct and vertical pressing by the press plate may induce an incomplete join of the back casing to the front frame or cracks at some joined portions. Furthermore, when the inexact alignment is worse, forcing the press plate to press down may not only damage the back casing or the front frame but also indirectly induce cracks in the displaying panel. For example, a constant stroke may induce an excessive large pressing force of the press plate; a damaged structure of the back casing or the front frame may indirectly induce cracks in the displaying panel.